Fold-down seat mechanism for vehicles

ABSTRACT

A folding seat mechanism for vehicles such as station wagons and panel trucks wherein a passenger seat is folded down so that the backs of both the seat back and seat cushion provide additional cargo carrying space. The mechanism includes torsion bars connected to bias the seat back into an upright position and a linkage mechanism joining the seat back and cushion and effective to transmit the folding motion of one into the folding motion of the other. The mechanism also includes latching mechanisms effective to hold the seat back and cushion in either an upright position or in a completely fold-down position, and suitable built-in load carrying supports.

United States Patent Derrickson, Jr. et a].

[ 51 June 13, 1972 [54] F OLD-DOWN SEAT MECHANISM FOR VEHICLES [72]lnventors: Charles Derrickson, Jr.; Robert A.

Rodgers, both of Fort Wayne, Ind.

[73] Assignee: International Harvester Company,

Chicago, 111.

[22] Filed: Aug. 21, 1970 [21] Appl. No.: 65,838

52 us. Cl ..296/66, 297/63 [51] Int. Cl ..B60n 1/10 [58] Field of Search..296/65, 66, 69; 297/63, 64, 297/105, 331, 333, 341

[56] References Cited UNITED STATES PATENTS 3,171,684 3/1965 Carte..296/65 X 2,987,344 6/1961 Hershey ..296/66 3,333,885 8/1967 Franke eta1 ..296/66 Caley ..296/66 Betts ..296/69 [57] ABSTRACT A folding seatmechanism for vehicles such as station wagons and panel trucks wherein apassenger seat is folded down so that the backs of both the seat backand seat cushion provide additional cargo carrying space. The mechanismincludes torsion bars connected to bias the seat back into an uprightposition and a linkage mechanism joining the seat back and cushion andeffective to transmit the folding motion of one into the folding motionof the other. The mechanism also includes latching mechanisms efiectiveto hold the seat back and cushion in either an upright position or in acompletely fold-down position, and suitable built-in load carryingsupports.

16 Claims, 7 Drawing Figures F OLD-DOWN SEAT MECHANISM FOR VEHICLESBACKGROUND OF THE INVENTION This invention relates to vehicle seats andmore particularly to passenger seats of the fold-down variety that areconvertible into cargo-carrying space.

In certain types of vehicles, such as station wagons and light passengertrucks, it is desirable to be able to convert the vehicle to provideadditional cargo carrying space when desired.

This conversion is most easily accomplished by providing one or morerear passenger seats that fold down to provide additional cargo space.Such folding seats are well known, as much for their complexity andawkward manipulation, as for their utility.

SUMMARY OF THE INVENTION It is an object of the present invention toprovide a folding seat mechanism that is simple to operate, rugged inoperation, and firmly latched in either the upright or completefold-down positions so as to minimize noise and vibration frequentlyencountered in such devices.

It is another object to incorporate a resilient torsion bar mountingmechanism biased to raise the seat back and cushion toward an uprightposition.

It is still another object to provide a pivoted seat back and pivotedseat cushion and linkage mechanism interconnecting the back and cushionand effective to move said back and seat simultaneously throughout aportion of their pivoting motion.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a view from the rear of thefold-down seat back of the present invention showing seat back releaseson either side;

FIG. 2 is a fragmentary perspective view showing one seat back releaseand portions of the mounting hinge and torsion bar for the seat back;

FIG. 3 shows the seat mounting mechanism in its normal and lockedposition;

FIG. 4 shows the seat cushion in its first stage of folding partiallyfolded forward to a limit of motion until the seat back is released;

FIG. 5 shows two torsion bars mounted to bias the seat back toward anupright position;

FIG. 6 shows the seat back released and partially folded forward, andthe seat cushion folded all the way down; and

FIG. 7 shows both the seat cushion and seat back in a complete foldedposition and folded down flush with the rear deck of the vehicle.

DESCRIPTION OF THE PREFERRED EMBODIMENT The seat back 11 carries tworelease latches l5 and 16 located on opposite sides of the back 11. Thelatch comprises a recessed finger well 17, a spring loaded handle 18pivotally mounted within the well 17 and connected to actuate a latchingbar 19. When the seat back 11 is upright, in the position shown in FIGS.1 and 2, the latching bar 19 is engaged by a latch 20 mounted on theinterior wall of the vehicle. Similarly, the release latch 16 comprisesa recessed well 23, a handle 24, and latching bar adapted to be engagedby a wall mounted latch 26.

The seat back 11 is mounted on the interior walls 28 and 29 of thevehicle by a pair of brackets 30 and 31 bolted or welded to therespective wall. A pair of mounting brackets 32 and 33 are rigidlyattached to the seat back 11 and are pivotally mounted on the brackets30 and 31, respectively. A pair of torsion bars 34 and 35 each have anoutermost end attached to the brackets 32 and 33, respectively. Theinnennost ends of the bars 34 and 35 are anchored to the vehicle body bya common clamp 36. The bars 34 and 35 are mounted under initial torsionand tend to bias the seat back 11 toward the upright position.

Referring now to FIG. 3, the seat cushion 12 is seen to be pivotallysupported by a stanchion 40 attached to the floor 37 of the vehicle anda link 41 pivotally attached to the stanchion 40 by pivotal connection41a and to a bracket 42 rigidly attached to the outer edge of the seatcushion 12. A corresponding stanchion, link and bracket are provided onthe opposite side of the seat cushion 12, but are not shown in thefigures.

An elongated connecting link or bar 44 joins the link 32 on the seatback 1 l to the bracket 42 on the seat cushion 12. The link 44 ispivotally attached to the link 32 by means of a pin 45 and to thebracket 42 by means of a pivot pin 46. An upwardly extending notchedprong 47 is formed integrally with the bar 44 for retaining the seatcushion 12 in its normal position for use as a seat. (A correspondinglink and attachments are provided for the opposite side of the seat butare not described here in detail.)

The link 44 curves downwardly at 50 so that most of the linkage andmounting brackets are disposed below the deck level 13 when the seatmechanism 10 is completely folded down. The bar 44 curves outwardly at51 so as to clear the wheel well 48 in the upright position, and toclear the curved portion 49 of the seat back 11 in the down position.The link 44 is also curved outwardly at 52 and inwardly at 53 so thatthe link 44 clears the top of the stanchion 40 when completely foldeddown.

A U-shaped channel bracket 55 is rigidly attached to the seat cushion l2and is adapted to extend over a central portion of the link 44 when theseat cushion 12 is in its normal position as best seen in FIG. 3. Alatching rod 56 extends through and across the entire width of the seatcushion 12 and is torsionally biased toward contact with the channelbracket 55. The ends of the rod 56 are formed into the shape of a crankat 57 to provide limited angular rotation of the rod 56. The outer legof U- shaped bracket 55 is bifurcated to form two stops 58 and 59. Thestop 58 limits the angular motion of the rod 56, and the stop 59provides a rest for the seat cushion '12 in the fold-down position. Whenthe seat cushion 12 is in the upright position, the crank end 57 of therod 56 engages the notched prong 47 and is held in this position untilit is manually released.

The bracket 42 is formed with a flange stop 60 which is adapted tocontact a notched shoulder 61 formed on the link 41. The stop 60 limitsthe angular rotation of the seat cushion 12 about the pin 46 when it isfolded forward.

The stanchion 40 carries a latching prong 65 on the upper end thereoffor locking with the rod 19 on the seat back 11 when the latter isfolded down. The stanchion 40 also carries a support flange 66 adaptedto be contacted by the link 44 to support weight that might be placed onthe backs of the seat 1 1 and cushion 12 in the fold-down position.

The operation of the fold-down seat mechanism 10 will now be described:

In the normal position for carrying passengers, the seat back 11 andcushion 12 are in the positions shown in FIGS. 1, 2, and 3. The seatmechanism 10 is converted to the cargo carrying position, shown in FIG.8, by first releasing manually the rod 56 from engagement with the prong47. The seat cushion 12 is then rotated forwardly about the axis definedby the pin 46 until the flange 60 engages the shoulder 61, as shown inFIG. 4. This is the limit of motion for the cushion 12 until the seatback 1 l is released.

The seat back 11 is released by unlatching the latches l5 and 16. Theseat back 11 is then folded forwardly against the torsion of the bars 34and 35. The forward folding motion of i engage a pin 67 mounted on thefloor of the vehicle or on a door pillar. Continued forward motion ofthe seat back 1 1 causes the rod 19 to engage the latch 65, and the link44 comes to rest on the support flange 66. The back edge of the seatcushion 12 is depressed along with the seat back 11 until it is flushwith the horizontal and with the rear deck 13. This latter motion alsoeffectively locks the seat cushion 12 to the pin 67 to prevent vibrationand noise from being generated by motion of the cushion 12. Similarly,the engagement of rod 19 with latch 65 effectively locks the seat back 1l.

The seat mechanism 10 is raised into the upright position by firstreleasing the latches l and 16. The torsion in the bars 34 and 35 tendto raise the seat back 11 and swing it back to the upright position. Therearward arcuate motion of the back 11 is transmitted through the link44, picking up the seat cushion l2, first by the rear to release pin-67,and then raising it to the position shown in FIG. 4. The bars 19 and 25engage the latches 20 and 26, respectively, and the seat back 11 is thuslocked in the upright position. The seat cushion 12 is merely flippedthe rest of the way backand the rod 56 engages the latching prong 47.The entire seat mechanism is then again in the passenger carryingposition.

It is to be understood that the linkage and latching mechanisms shownand described exist on both sides of the seat mechanism, and are onlydescribed where clearly visible.

The embodiment shown and described is by way of example only and theinvention is not to be considered as limited thereto except insofar asthe claims may be so limited. It is to be understood that many changesmay be made thereto without departing from the spirit of the invention.

1 claim:

1. A three-bar linkage for mounting a fold-down seat arrangement havinga seat back and seat cushion in a vehicle with interior walls and floorand comprising a first bar pivotally attached at one end to the interiorwall and rigidly attached at the other end to said seat back;

a second bar pivotally attached at one end to the floor and pivotallyattached at the other to said seat cushion;

a third bar pivotally connected to said first and second bars;

stop means attached to said seat cushion and engageable by said secondbar and effective to limit pivotal folding motion of said seat cushion;and

interconnecting means effective to cause the pivotal motion of saidfirst bar to be transmitted through said third bar so as to causefurther folding motion of said seat cushion integrally with said secondbar.

2. A folding seat mechanism for a vehicle having an interior floor andside walks comprising;

a seat back;

a seat cushion;

a first pivotal mounting linkage attached to the side walls andsupporting said seat back;

a second pivotal mounting linkage attached to the floor and supportingsaid seat cushion;

a third connecting linkage operatively connecting said first and secondmounting linkages;

stop means incorporated in said second linkage and efiec tive to limitthe pivotal forward folding motion of said seat cushion;

said seat cushion has defined a forward leading edge when said cushionis folded forwardly to the limit of motion 1 permitted by said stopmeans;

engageable latch means mounted on said seat cushion adjacent saidleading edge; and 1 mating latch means mounted on the vehicle andengageable by said last named latch means.

3. The folding seat mechanism of claim 2 wherein release and forwardfolding motion of said seat back is transmitted through said thirdconnecting linkage to said seat cushion to cause further forward foldingmotion thereof.

4. The folding seat mechanism of claim 3 wherein said second and thirdpivotal mounting linkages constrain said seat cushion to fold forwardlyso that said leading edge of said seat cushion drops initially below ahorizontal plane so as to permit the engagement of said engageable andmating latch means; and

further forward folding motion of said seat back effectively drops thebacks of said seat back and cushion to a common horizontal plane andeffectively locks said engageable and mating latch means to minimizevibrational motion of said seat cushion.

5. A folding seat mechanism for a vehicle having an interior floor andside walls comprising;

a seat back;

a seat cushion;

a first pivotal mounting linkage attached to the side walls andsupporting said seat back;

a second pivotal mounting linkage attached to the floor and supportingsaid seat cushion;

a third connecting linkage operatively connecting said first and secondmounting linkages;

stop means incorporated in said second linkage and effective to limitthe pivotal forward folding motion of said seat cushion;

releasable latch means associated with said seat back and effective tolatch firmly said seat back to the side walls in an upright position; i

a floor mounted stanchion for mounting said second pivotal linkage; and

additional latch means also mounted on said stanchion and engageable bysaid releasable latch means on said seat back to latch said seat backfirmly in a completely folddown position.

6. The folding seat mechanism of claim 5 including a load bearing flangemounted on said stanchion and engageable by said third connectinglinkage so as to provide a load bearing support for loads carried on thebacks of said seat cushion and seat back in the fold-down position;

body whereby said seat back is swingable between an.

upright position and a generally horizontal lowered position about afixed, transversely extending axis;

a generally transversely extending seat cushion; g

means operatively connecting said seat cushion to the vehicle bodywhereby said seat cushion is movable between a normal position whereinone lateral edge thereof is adjacent the lateral edge of said seat backwhich is lowermost when in its upright position and one side thereof isfacing generally upwardly and an extended, folded-down position whereinsaid one lateral edge thereof is horizontally spaced from said lateraledge of said seat back which is lowermost when in its upright positionand the side opposite said one side of said seat cushion is facinggenerally upwardly, said means including a first link having one endpivotally connected to said seat cushion and its opposite end pivotallyconnected to a part stationary with respect to the vehicle body, saidmovement of said seat cushion between its normal and folded-downpositions being effected by relative pivotal movement between said seatcushion and said first link and between said first link and I said partstationary with respect to the vehicle body; and linkage meansoperatively interconnecting said seat back and said first link wherebysaid first link is constrained to pivot in respect to said partstationary with respect to the vehicle body only in unison with saidseat back as said seat back is swung between its upright and loweredposimitted between said seat cushion and said first link during suchmovement of said seat cushion from its normal position to its loweredposition.

9. A folding seat structure as set forth in claim 8, includingreleasable latch means associated with said seat back, the vehicle body,and said part stationary with respect to the vehicle body, said latchmeans being operable to firmly latch said seat back to the vehicle bodywhen in its upright position and to said part stationary with respect tothe vehicle body when in its lowered position.

10. A folding seat structure as set forth in claim 9, including torsionspring means operatively connected to the vehicle body and said seatback, said torsion spring means being effective to continually bias saidseat back toward its upright position, said spring means includes a pairof torsion bars, each of said torsion bars extending transversely inopposite directions from a mid-point of the vehicle body, the innermostend of each torsion bar being firmly secured to the vehicle body by acommon clamp and the outermost end of each torsion bar being attached tosaid seat back.

1 l. A folding seat structure as set forth in claim 9, includingadditional releasable latch means associated with said seat cushion andsaid linkage means, said latch means being operable to firmly latch saidseat cushion to said linkage means when said seat cushion is in itsnormal position.

12. A folding seat structure as set forth in claim 11, wherein saidlinkage means includes a second link having one end pivotally connectedto said seat back and its opposite end pivotally connected to said firstlink.

13. A folding seat structure as set forth in claim 12, wherein saidsecond link is capable of pivoting with respect to said seat back aboutan axis vertically spaced from the axis about which said seat backpivots as it swings between its upright and lowered positions, saidsecond link being further capable of pivoting with respect to said firstlink about an axis coincident with the axis about which said seatcushion is capable of pivoting with respect to said first link as itmoves between its normal and folded-down positions.

14. A folding seat structure as set forth in claim 13, including supportmeans for said seat cushion when in its normal position, said supportmeans including a substantially U- shaped bracket rigidly secured tosaid seat cushion, said bracket being formed with spaced and parallelleg portions integrally connected along respective edges by a bightportion, the leg portions of said bracket being disposed on respectiveopposite sides of said second link and the bight portion thereofabutting an edge portion of said second link when said seat cushion isin its normal position.

15. A folding seat structure as set forth in claim 14, includingadditional support and latch means for said seat cushion when in itsfolded-down position, said additional support and latch means includingsaid U-shaped bracket and a transversely extending pin rigidly securedto the vehicle body, one of said leg portions of said U-shaped bracketbeing bifurcated, said pin being receivable in the bifurcation andengageable with the edge surfaces of said one leg portion defining thebifurcation when said seat cushion is in its folded-down position.

16. A folding seat structure as set forth in claim 15, wherein said partstationary with respect to the vehicle body is in the form of astanchion rigidly secured to the vehicle body; and further includingsecond support means for said seat cushion when in its folded-downposition comprising a transversely projecting flange rigidly secured tosaid stanchion, an edge portion of said second link resting upon saidflange when said seat cushion is in its folded-down position.

1. A three-bar linkage for mounting a fold-down seat arrangement havinga seat back and seat cushion in a vehicle with interior walls and floorand comprising a first bar pivotally attached at one end to the interiorwall and rigidly attached at the other end to said seat back; a secondbar pivotally attached at one end to the floor and pivotally attached atthe other to said seat cushion; a third bar pivotally connected to saidfirst and second bars; stop means attached to said seat cushion andengageable by said second bar and effective to limit pivotal foldingmotion of said seat cushion; and interconnecting means effective tocause the pivotal motion of said first bar to be transmitted throughsaid third bar so as to cause further folding motion of said seatcushion integrally with said second bar.
 2. A folding seat mechanism fora vehicle having an interior floor and side walks comprising; a seatback; a seat cushion; a first pivotal mounting linkage attached to theside walls and supporting saiD seat back; a second pivotal mountinglinkage attached to the floor and supporting said seat cushion; a thirdconnecting linkage operatively connecting said first and second mountinglinkages; stop means incorporated in said second linkage and effectiveto limit the pivotal forward folding motion of said seat cushion; saidseat cushion has defined a forward leading edge when said cushion isfolded forwardly to the limit of motion permitted by said stop means;engageable latch means mounted on said seat cushion adjacent saidleading edge; and mating latch means mounted on the vehicle andengageable by said last named latch means.
 3. The folding seat mechanismof claim 2 wherein release and forward folding motion of said seat backis transmitted through said third connecting linkage to said seatcushion to cause further forward folding motion thereof.
 4. The foldingseat mechanism of claim 3 wherein said second and third pivotal mountinglinkages constrain said seat cushion to fold forwardly so that saidleading edge of said seat cushion drops initially below a horizontalplane so as to permit the engagement of said engageable and mating latchmeans; and further forward folding motion of said seat back effectivelydrops the backs of said seat back and cushion to a common horizontalplane and effectively locks said engageable and mating latch means tominimize vibrational motion of said seat cushion.
 5. A folding seatmechanism for a vehicle having an interior floor and side wallscomprising; a seat back; a seat cushion; a first pivotal mountinglinkage attached to the side walls and supporting said seat back; asecond pivotal mounting linkage attached to the floor and supportingsaid seat cushion; a third connecting linkage operatively connectingsaid first and second mounting linkages; stop means incorporated in saidsecond linkage and effective to limit the pivotal forward folding motionof said seat cushion; releasable latch means associated with said seatback and effective to latch firmly said seat back to the side walls inan upright position; a floor mounted stanchion for mounting said secondpivotal linkage; and additional latch means also mounted on saidstanchion and engageable by said releasable latch means on said seatback to latch said seat back firmly in a completely fold-down position.6. The folding seat mechanism of claim 5 including a load bearing flangemounted on said stanchion and engageable by said third connectinglinkage so as to provide a load bearing support for loads carried on thebacks of said seat cushion and seat back in the fold-down position. 7.In a vehicle body, a folding seat structure, comprising, a generallytransversely extending seat back; means pivotally connecting said seatback to the vehicle body whereby said seat back is swingable between anupright position and a generally horizontal lowered position about afixed, transversely extending axis; a generally transversely extendingseat cushion; means operatively connecting said seat cushion to thevehicle body whereby said seat cushion is movable between a normalposition wherein one lateral edge thereof is adjacent the lateral edgeof said seat back which is lowermost when in its upright position andone side thereof is facing generally upwardly and an extended,folded-down position wherein said one lateral edge thereof ishorizontally spaced from said lateral edge of said seat back which islowermost when in its upright position and the side opposite said oneside of said seat cushion is facing generally upwardly, said meansincluding a first link having one end pivotally connected to said seatcushion and its opposite end pivotally connected to a part stationarywith respect to the vehicle body, said movement of said seat cushionbetween its normal and folded-down positions being effected by relativepivotal movement between said seat cushion anD said first link andbetween said first link and said part stationary with respect to thevehicle body; and linkage means operatively interconnecting said seatback and said first link whereby said first link is constrained to pivotin respect to said part stationary with respect to the vehicle body onlyin unison with said seat back as said seat back is swung between itsupright and lowered positions.
 8. A folding seat structure as set forthin claim 7, including stop means carried by said seat cushion andengageable with said first link during movement of said seat cushionfrom its normal position toward its folded-down position, said stopmeans being effective to limit relative pivotal movement permittedbetween said seat cushion and said first link during such movement ofsaid seat cushion from its normal position to its lowered position.
 9. Afolding seat structure as set forth in claim 8, including releasablelatch means associated with said seat back, the vehicle body, and saidpart stationary with respect to the vehicle body, said latch means beingoperable to firmly latch said seat back to the vehicle body when in itsupright position and to said part stationary with respect to the vehiclebody when in its lowered position.
 10. A folding seat structure as setforth in claim 9, including torsion spring means operatively connectedto the vehicle body and said seat back, said torsion spring means beingeffective to continually bias said seat back toward its uprightposition, said spring means includes a pair of torsion bars, each ofsaid torsion bars extending transversely in opposite directions from amid-point of the vehicle body, the innermost end of each torsion barbeing firmly secured to the vehicle body by a common clamp and theoutermost end of each torsion bar being attached to said seat back. 11.A folding seat structure as set forth in claim 9, including additionalreleasable latch means associated with said seat cushion and saidlinkage means, said latch means being operable to firmly latch said seatcushion to said linkage means when said seat cushion is in its normalposition.
 12. A folding seat structure as set forth in claim 11, whereinsaid linkage means includes a second link having one end pivotallyconnected to said seat back and its opposite end pivotally connected tosaid first link.
 13. A folding seat structure as set forth in claim 12,wherein said second link is capable of pivoting with respect to saidseat back about an axis vertically spaced from the axis about which saidseat back pivots as it swings between its upright and lowered positions,said second link being further capable of pivoting with respect to saidfirst link about an axis coincident with the axis about which said seatcushion is capable of pivoting with respect to said first link as itmoves between its normal and folded-down positions.
 14. A folding seatstructure as set forth in claim 13, including support means for saidseat cushion when in its normal position, said support means including asubstantially U-shaped bracket rigidly secured to said seat cushion,said bracket being formed with spaced and parallel leg portionsintegrally connected along respective edges by a bight portion, the legportions of said bracket being disposed on respective opposite sides ofsaid second link and the bight portion thereof abutting an edge portionof said second link when said seat cushion is in its normal position.15. A folding seat structure as set forth in claim 14, includingadditional support and latch means for said seat cushion when in itsfolded-down position, said additional support and latch means includingsaid U-shaped bracket and a transversely extending pin rigidly securedto the vehicle body, one of said leg portions of said U-shaped bracketbeing bifurcated, said pin being receivable in the bifurcation andengageable with the edge surfaces of said one leg portion defining thebifurcation when said seat cushion is in its folded-down poSition.
 16. Afolding seat structure as set forth in claim 15, wherein said partstationary with respect to the vehicle body is in the form of astanchion rigidly secured to the vehicle body; and further includingsecond support means for said seat cushion when in its folded-downposition comprising a transversely projecting flange rigidly secured tosaid stanchion, an edge portion of said second link resting upon saidflange when said seat cushion is in its folded-down position.